Couplers and coupling systems for front-end loaders are well-known and widely used to provide for quick connect/disconnect of attachments, such as buckets, forks or the like, to the arms and tilt control linkage of a front-end loader or like machine. As used herein, the term “front-end loader” is intended to encompass front-end loaders and all other tractors and machines including two laterally spaced-apart arms and one or more tilt control cylinders, links, or the like that control the angular position of a male coupler portion and/or an attachment pivotally secured to the arms. Examples of known couplers and coupling systems of the general type disclosed herein can be found in commonly owned U.S. Pat. Nos. 4,708,579; 5,415,235; 5,529,419; and 5,692,850, the disclosures of which are hereby expressly incorporated by reference herein.
As is widely known in connection with loader coupling systems, a male coupler portion is operatively connected to the arms and control linkage of a front-end loader machine. The female coupler portion is defined by two parallel, spaced-apart ribs that are welded to otherwise fixedly secured to a bucket or other attachment such as forks or the like. Thus, the front-end loader is able to couple with any desired attachment by mating the male coupler portion to the female coupler portion of a desired attachment for use of the attachment.
FIG. 1A illustrates a first type of conventional female rib FR1. As is known in the art and as shown in FIG. 1C, two of the ribs FR1 are welded or otherwise fixedly secured vertically to a bucket or other attachment AT in parallel, spaced-apart relation to define a first type of female coupler portion B. Each rib FR1 comprises a hook portion FH1 and an ear portion FT1 spaced from the hook portion, but lying in the same plane therewith. The ear portion FT1 includes a lock aperture FA1 that extends transversely therethrough. In use, the hook portion FH1 is adapted to receive a mounting pin or other mounting member of a male coupler portion. The hook portion FH1 and mounting member of the male coupler portion typically comprise mating cylindrical surfaces. When the hook portion FH1 is seated on the mounting pin/member of the male coupler portion, the ear portion FT1 of the rib moves into a locking region of the male coupler portion where it is engaged by a lock mechanism to secure the rib FR1 to the male coupler portion in a releasable fashion. Typically, the lock mechanism comprises a plunger pin that is slidably received in the lock aperture FA1 of the ear FT1 so as to prevent withdrawal of the ear from the locking region of the male coupler portion which, in turn, prevents separation of the hook portion FH1 from the mounting pin/member that is seated therein. As noted, in practice, first and second ribs FR1 are used to define a female coupler portion B and, thus, the mating male coupler portion includes respective first and second mounting locations, and first and second lock mechanisms, to secure the ribs to the male coupler portion. The female rib FR1 shown in FIG. 1A is commonly referred to as a JRB-style rib in that two of the ribs FR1 arranged in an appropriate manner define a female coupler portion that is engageable by a male coupler portion available commercially from JRB Company, Inc., Akron, Ohio, U.S.A.
FIG. 1B partially illustrates a second type of conventional female rib FR2. As is known in the art, two vertical ribs FR2 are welded or otherwise fixedly secured to a bucket or other attachment in parallel, spaced-apart relation to define a second type of female coupler portion in the same arrangement as shown for the female coupler portion B in FIG. 1C. The rib FR2 functions similarly to the rib FR1 but is shaped, and dimensioned differently, and the ribs FR2 are spaced differently relative to each other laterally to define a female coupler portion as compared to the ribs FR1. Each rib FR2 comprises a hook portion FH2 and an ear portion FT2 spaced from the hook portion but in the same plane therewith. The ear portion FT2 includes a transverse lock aperture FA2 that extends therethrough. In use, the hook portion FH2 is adapted to receive a mounting pin or other mounting member of a male coupler portion. The hook portion FH2 and mounting member of the male coupler portion typically comprise mating cylindrical surfaces. When the hook portion FH2 is seated on the mounting pin/member of the male coupler portion, the ear portion FT2 moves into a locking region of the male coupler portion where it is engaged by a lock mechanism to secure the rib FR2 to the male coupler portion. Here, again, the lock mechanism of the male coupler portion typically comprises a plunger pin that is slidably received in the lock aperture FA2 of the tongue FT2 so as to prevent withdrawal of the ear FT2 from the locking region of the male coupler portion which, in turn, prevents separation of the hook portion FH2 from the mounting pin/member that is seated therein. As noted, in practice, first and second ribs FR2 are used to define a female coupler portion and, thus, the mating male coupler portion includes first and second mounting members, and first and second lock mechanisms, to secure the ribs to the male coupler portion. The female rib FR2 shown in FIG. 1B is commonly referred to as a CAT-style rib in that two of the ribs FR2 arranged in an appropriate manner define a female coupler portion that is engageable by a male coupler portion available commercially from Caterpillar Inc., Peoria, Ill., U.S.A.
A problem arises with known male coupler portions in that they have heretofore been dedicated to a particular type of female coupler portion. As such, known male coupler portions can only be used to pick-up attachments having the required female rib arrangement. In the field or as part of an equipment rental fleet operation, this limits the use of a particular front-end loader and/or requires the male coupler portion to be changed at the pin-on connection which is highly undesirable.
According to the present invention, a hybrid male coupler portion for a front-end loader is provided and operable to mate selectively and interchangeably with first and second different female coupler portions.